The vaccine was 88% effective at preventing pertussis among infants younger than 2 months when administered during the third trimester of pregnancy.
The FDA has approved Adacel (tetanus toxoid, reduced diptheria toxoid, and acellular pertussis vaccine; Tdap) during the third trimester of pregnancy to help protect against pertussis in infants younger than 2 months of age.
The Adacel vaccine is FDA-approved for active booster immunization against tetanus, diphtheria, and pertussis in individuals ages 10 through 64 years. It was the first vaccine globally to have a licensed indication for use in pregnancy to help prevent pertussis in young infants.
Pertussis is a highly contagious respiratory infection. Very young infants are at the highest risk of complications due to pertussis because of their still developing immune systems, and nearly half of babies ages 6 months and younger who get pertussis may need care in the hospital. Additionally, 1 out of 100 infants hospitalized for pertussis dies.
Although it can be prevented with vaccination, pertussis often goes undiagnosed. It can lead to severe and sometimes life-threatening health problems, such as exacerbation of chronic medical conditions such as asthma. For children and adults, initial symptoms typically develop between 7 and 10 days after exposure and are the same as a common cold. The next stage of illness is characterized by frequent bouts of paroxysmal cough and inspiratory whooping.
The CDC recommends Tdap vaccination during every pregnancy. When given during the third trimester, Adacel can help pregnant individuals create antibodies against the bacteria that cause pertussis, which are passed to the infant before birth. These antibodies help protect the infant against whooping cough during the first few months of life.
The efficacy of Adacel when administered during the third trimester to prevent pertussis among infants younger than 2 months of age was established in a clinical study using innovative real-world data, according to a press release. In that study, the efficacy of the vaccine at preventing pertussis was found to be 88%.
Available safety data in the retrospective passive surveillance study and ongoing pregnancy registry during the third trimester of pregnancy did not reveal any vaccine-related adverse effects on pregnancy or on the fetus or infant.
“We are pleased to receive the FDA’s approval for use of Adacel vaccine specifically during pregnancy to help protect young infants against pertussis, a potentially life-threatening disease,” said Michael Greenberg, MD, MPH, North America Medical Head of Vaccines at Sanofi, in the press release. “We pursued the label expansion to align fully with the long-standing health agency recommendations to provide Tdap vaccination to every woman in every pregnancy. We hope for higher and higher rates of Tdap vaccination in pregnancy so that fewer and fewer infants are likely to get pertussis.”
FDA approves Adacel for immunization during pregnancy to help protect young infants against pertussis. News release. Sanofi; January 17, 2023. Accessed January 17, 2023. https://www.news.sanofi.us/2023-01-17-FDA-approves-Adacel-R-for-immunization-during-pregnancy-to-help-protect-young-infants-against-pertussis